CVE-2026-33150

Name	CVE-2026-33150
Description	libfuse is the reference implementation of the Linux FUSE. From version 3.18.0 to before version 3.18.2, a use-after-free vulnerability in the io_uring subsystem of libfuse allows a local attacker to crash FUSE filesystem processes and potentially execute arbitrary code. When io_uring thread creation fails due to resource exhaustion (e.g., cgroup pids.max), fuse_uring_start() frees the ring pool structure but stores the dangling pointer in the session state, leading to a use-after-free when the session shuts down. The trigger is reliable in containerized environments where cgroup pids.max limits naturally constrain thread creation. This issue has been patched in version 3.18.2.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
fuse3 (PTS)	bullseye	3.10.3-2	fixed
	bookworm	3.14.0-4	fixed
	trixie	3.17.2-3	fixed
	forky	3.18.1-1	vulnerable
	sid	3.18.2-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
fuse3	source	bullseye	(not affected)
fuse3	source	bookworm	(not affected)
fuse3	source	trixie	(not affected)
fuse3	source	(unstable)	3.18.2-1

Notes

[trixie] - fuse3 <not-affected> (Vulnerable code not present)
[bookworm] - fuse3 <not-affected> (Vulnerable code not present)
[bullseye] - fuse3 <not-affected> (Vulnerable code not present)
https://github.com/libfuse/libfuse/security/advisories/GHSA-qxv7-xrc2-qmfx
Fixed by: https://github.com/libfuse/libfuse/commit/49fcd891a58f622c098e2ca67d66086f7b213836 (fuse-3.18.2)